Hello! I'm a noob at python and pygame, also forgive for possible english mistakes, i'm actually from Brasil. I'm creating a plataform game using tilemaps and loading it with Richard's Jones tmx library, and i have come across a "bug": When i'm moving my character around, he goes faster to the left and down directions. First, i thought it was an error with my code, but after making differents test's using 20-scenes.py, written by Richard Jones, i've realized that this problem ocurrs with his game. If you press both the left and the right arrows together you will see that the caracter has the tendency of going left, also all the objects (Bullet, enemy, Player...) can't have a speed bellow 20 pixels/second (in my game, you can't set a speed bellow 31 pixels/second) otherwize it can't move to the right direction. What is the source of the problem? How do i fix it?